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26***********************************************************************/
27
28#ifdef HAVE_CONFIG_H
29#include "config.h"
30#endif
31
32/**********************************************************************
33 * Correlation Matrix Computations for LS estimate.
34 **********************************************************************/
35
36#include "main_FIX.h"
37
38/* Calculates correlation vector X'*t */
39void silk_corrVector_FIX(
40    const opus_int16                *x,                                     /* I    x vector [L + order - 1] used to form data matrix X                         */
41    const opus_int16                *t,                                     /* I    Target vector [L]                                                           */
42    const opus_int                  L,                                      /* I    Length of vectors                                                           */
43    const opus_int                  order,                                  /* I    Max lag for correlation                                                     */
44    opus_int32                      *Xt,                                    /* O    Pointer to X'*t correlation vector [order]                                  */
45    const opus_int                  rshifts                                 /* I    Right shifts of correlations                                                */
46)
47{
48    opus_int         lag, i;
49    const opus_int16 *ptr1, *ptr2;
50    opus_int32       inner_prod;
51
52    ptr1 = &x[ order - 1 ]; /* Points to first sample of column 0 of X: X[:,0] */
53    ptr2 = t;
54    /* Calculate X'*t */
55    if( rshifts > 0 ) {
56        /* Right shifting used */
57        for( lag = 0; lag < order; lag++ ) {
58            inner_prod = 0;
59            for( i = 0; i < L; i++ ) {
60                inner_prod += silk_RSHIFT32( silk_SMULBB( ptr1[ i ], ptr2[i] ), rshifts );
61            }
62            Xt[ lag ] = inner_prod; /* X[:,lag]'*t */
63            ptr1--; /* Go to next column of X */
64        }
65    } else {
66        silk_assert( rshifts == 0 );
67        for( lag = 0; lag < order; lag++ ) {
68            Xt[ lag ] = silk_inner_prod_aligned( ptr1, ptr2, L ); /* X[:,lag]'*t */
69            ptr1--; /* Go to next column of X */
70        }
71    }
72}
73
74/* Calculates correlation matrix X'*X */
75void silk_corrMatrix_FIX(
76    const opus_int16                *x,                                     /* I    x vector [L + order - 1] used to form data matrix X                         */
77    const opus_int                  L,                                      /* I    Length of vectors                                                           */
78    const opus_int                  order,                                  /* I    Max lag for correlation                                                     */
79    const opus_int                  head_room,                              /* I    Desired headroom                                                            */
80    opus_int32                      *XX,                                    /* O    Pointer to X'*X correlation matrix [ order x order ]                        */
81    opus_int                        *rshifts                                /* I/O  Right shifts of correlations                                                */
82)
83{
84    opus_int         i, j, lag, rshifts_local, head_room_rshifts;
85    opus_int32       energy;
86    const opus_int16 *ptr1, *ptr2;
87
88    /* Calculate energy to find shift used to fit in 32 bits */
89    silk_sum_sqr_shift( &energy, &rshifts_local, x, L + order - 1 );
90    /* Add shifts to get the desired head room */
91    head_room_rshifts = silk_max( head_room - silk_CLZ32( energy ), 0 );
92
93    energy = silk_RSHIFT32( energy, head_room_rshifts );
94    rshifts_local += head_room_rshifts;
95
96    /* Calculate energy of first column (0) of X: X[:,0]'*X[:,0] */
97    /* Remove contribution of first order - 1 samples */
98    for( i = 0; i < order - 1; i++ ) {
99        energy -= silk_RSHIFT32( silk_SMULBB( x[ i ], x[ i ] ), rshifts_local );
100    }
101    if( rshifts_local < *rshifts ) {
102        /* Adjust energy */
103        energy = silk_RSHIFT32( energy, *rshifts - rshifts_local );
104        rshifts_local = *rshifts;
105    }
106
107    /* Calculate energy of remaining columns of X: X[:,j]'*X[:,j] */
108    /* Fill out the diagonal of the correlation matrix */
109    matrix_ptr( XX, 0, 0, order ) = energy;
110    ptr1 = &x[ order - 1 ]; /* First sample of column 0 of X */
111    for( j = 1; j < order; j++ ) {
112        energy = silk_SUB32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ L - j ], ptr1[ L - j ] ), rshifts_local ) );
113        energy = silk_ADD32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ -j ], ptr1[ -j ] ), rshifts_local ) );
114        matrix_ptr( XX, j, j, order ) = energy;
115    }
116
117    ptr2 = &x[ order - 2 ]; /* First sample of column 1 of X */
118    /* Calculate the remaining elements of the correlation matrix */
119    if( rshifts_local > 0 ) {
120        /* Right shifting used */
121        for( lag = 1; lag < order; lag++ ) {
122            /* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
123            energy = 0;
124            for( i = 0; i < L; i++ ) {
125                energy += silk_RSHIFT32( silk_SMULBB( ptr1[ i ], ptr2[i] ), rshifts_local );
126            }
127            /* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
128            matrix_ptr( XX, lag, 0, order ) = energy;
129            matrix_ptr( XX, 0, lag, order ) = energy;
130            for( j = 1; j < ( order - lag ); j++ ) {
131                energy = silk_SUB32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ), rshifts_local ) );
132                energy = silk_ADD32( energy, silk_RSHIFT32( silk_SMULBB( ptr1[ -j ], ptr2[ -j ] ), rshifts_local ) );
133                matrix_ptr( XX, lag + j, j, order ) = energy;
134                matrix_ptr( XX, j, lag + j, order ) = energy;
135            }
136            ptr2--; /* Update pointer to first sample of next column (lag) in X */
137        }
138    } else {
139        for( lag = 1; lag < order; lag++ ) {
140            /* Inner product of column 0 and column lag: X[:,0]'*X[:,lag] */
141            energy = silk_inner_prod_aligned( ptr1, ptr2, L );
142            matrix_ptr( XX, lag, 0, order ) = energy;
143            matrix_ptr( XX, 0, lag, order ) = energy;
144            /* Calculate remaining off diagonal: X[:,j]'*X[:,j + lag] */
145            for( j = 1; j < ( order - lag ); j++ ) {
146                energy = silk_SUB32( energy, silk_SMULBB( ptr1[ L - j ], ptr2[ L - j ] ) );
147                energy = silk_SMLABB( energy, ptr1[ -j ], ptr2[ -j ] );
148                matrix_ptr( XX, lag + j, j, order ) = energy;
149                matrix_ptr( XX, j, lag + j, order ) = energy;
150            }
151            ptr2--;/* Update pointer to first sample of next column (lag) in X */
152        }
153    }
154    *rshifts = rshifts_local;
155}
156
157